/*
 * JBoss, Home of Professional Open Source
 * Copyright 2011, Red Hat, Inc. and individual contributors
 * by the @authors tag. See the copyright.txt in the distribution for a
 * full listing of individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */

package org.mobicents.protocols.ss7.m3ua.impl;

import javolution.util.FastList;
import javolution.util.FastSet;

import org.apache.log4j.Logger;
import org.mobicents.protocols.ss7.m3ua.ExchangeType;
import org.mobicents.protocols.ss7.m3ua.Functionality;
import org.mobicents.protocols.ss7.m3ua.impl.fsm.FSM;
import org.mobicents.protocols.ss7.m3ua.impl.fsm.State;
import org.mobicents.protocols.ss7.m3ua.impl.fsm.StateEventHandler;
import org.mobicents.protocols.ss7.m3ua.impl.fsm.UnknownTransitionException;
import org.mobicents.protocols.ss7.m3ua.message.MessageClass;
import org.mobicents.protocols.ss7.m3ua.message.MessageType;
import org.mobicents.protocols.ss7.m3ua.message.mgmt.Notify;
import org.mobicents.protocols.ss7.m3ua.parameter.Status;

/**
 * {@link RemAsStatePenTimeout#onEvent(State)} is called when the pending timer
 * T(r) expires.
 * 
 * @author amit bhayani
 * 
 */
public class RemAsStatePenTimeout implements StateEventHandler {

	private As as;
	private FSM fsm;
	private static final Logger logger = Logger.getLogger(RemAsStatePenTimeout.class);

	boolean inactive = false;

	public RemAsStatePenTimeout(As as, FSM fsm) {
		this.as = as;
		this.fsm = fsm;
	}

	/**
	 * <p>
	 * An active ASP has transitioned to ASP-INACTIVE or ASP DOWN and it was the
	 * last remaining active ASP in the AS. A recovery timer T(r) SHOULD be
	 * started, and all incoming signalling messages SHOULD be queued by the
	 * SGP. If an ASP becomes ASP-ACTIVE before T(r) expires, the AS is moved to
	 * the AS-ACTIVE state, and all the queued messages will be sent to the ASP.
	 * </p>
	 * <p>
	 * If T(r) expires before an ASP becomes ASP-ACTIVE, and the SGP has no
	 * alternative, the SGP may stop queuing messages and discard all previously
	 * queued messages. The AS will move to the AS-INACTIVE state if at least
	 * one ASP is in ASP-INACTIVE; otherwise, it will move to AS-DOWN state.
	 * </p>
	 */
	public void onEvent(State state) {
		this.inactive = false;

		// Clear the Pending Queue for this As
		this.as.clearPendingQueue();

		// check if there are any ASP's who are INACTIVE, transition to
		// INACTIVE else DOWN
		for (FastList.Node<Asp> n = this.as.getAspList().head(), end = this.as.getAspList().tail(); (n = n.getNext()) != end;) {
			Asp remAspImpl = n.getValue();
			
			FSM aspPeerFSM = remAspImpl.getPeerFSM();
			AspState aspState = AspState.getState(aspPeerFSM.getState().getName());
			
			if (aspState == AspState.INACTIVE) {
				try {

					if (!this.inactive) {
						this.fsm.signal(TransitionState.AS_INACTIVE);
						inactive = true;
					}
					
					if(this.as.getFunctionality() != Functionality.IPSP){
						Notify msg = createNotify(remAspImpl);
						remAspImpl.getAspFactory().write(msg);
					}
				} catch (UnknownTransitionException e) {
					logger.error(String.format("Error while translating Rem AS to INACTIVE. %s", this.fsm.toString()),
							e);
				}

			}// if (remAspImpl.getState() == AspState.INACTIVE)
		}// for

		if (!this.inactive) {
			// else transition to DOWN
			try {
				this.fsm.signal(TransitionState.AS_DOWN);
				inactive = true;
			} catch (UnknownTransitionException e) {
				logger.error(String.format("Error while translating Rem AS to DOWN. %s", this.fsm.toString()), e);
			}
		}
		
		//We want to pass MTP3 PAUSE only for SE. If its DE the peer transition handler will take care of MTP3 PAUSE
		if(as.getExchangeType() == ExchangeType.SE){
			FastSet<AsStateListener> asStateListeners = this.as.getAsStateListeners();
			for (FastSet.Record r = asStateListeners.head(), end = asStateListeners.tail(); (r = r.getNext()) != end;) {
				AsStateListener asAsStateListener = asStateListeners.valueOf(r);
				try {
					asAsStateListener.onAsInActive(this.as);
				} catch (Exception e) {
					logger.error(String.format("Error while calling AsStateListener=%s onAsInActive method for As=%s",
							asAsStateListener, this.as));
				}
			}
		}
	}

	private Notify createNotify(Asp remAsp) {
		Notify msg = (Notify) this.as.getMessageFactory().createMessage(MessageClass.MANAGEMENT, MessageType.NOTIFY);

		Status status = this.as.getParameterFactory().createStatus(Status.STATUS_AS_State_Change,
				Status.INFO_AS_INACTIVE);
		msg.setStatus(status);

		if (remAsp.getASPIdentifier() != null) {
			msg.setASPIdentifier(remAsp.getASPIdentifier());
		}

		msg.setRoutingContext(this.as.getRoutingContext());

		return msg;
	}

}
